Marine Weather and Tide Forecast for North Bay, WI

UPDATE
Issued 655 AM CDT Sun Apr 19 2026

No major changes to the going forecast.

Currently monitoring some scattered light radar returns approaching from the northwest, with plenty of dry air beneath it preventing most of it from reaching the ground (virga). That said, a snow flurry / rain sprinkle this morning remains possible in southern WI.

Sheppard

SHORT TERM
Issued 1125 PM CDT Sat Apr 18 2026

Rest of Tonight through Monday:

Winds have decoupled and will remain light under clear skies overnight. Looking at temps to dip down into the lower 30s under this clear and calm conditions. Although the official green up and growing has not been declared yet for southern WI, could see patchy to areas of frost develop overnight tonight.

Will see winds pick back up for Sunday as a mid-level shortwave trough swings through the region during the morning. Given this wave and just enough moisture may be enough to squeak out a few scattered light showers through the morning. Given the cooler temps could see a few flurries/mix as well, but overall not expecting much if any in the way of accumulations/impacts.
Otherwise it will become breezy through the afternoon with temps similar to today and topping off in the 40s again. Will be another chilly night Sunday night as high pressure builds into the Upper Midwest. Calm winds, subsidence, and temps at to below freezing may result in additional frost development into early Monday morning.

High pressure works its way overhead and then eastward for Monday and will begin to see temps climb back into the 50s for Monday as southerly flow returns on the backside of the departing high.

Wagner

LONG TERM
Issued 1125 PM CDT Sat Apr 18 2026

Monday night through Saturday:

Overall fairly quiet pattern through midweek with temps gradually warming up to above normal. Start to see temps in the 70s return on Tuesday during the day as the upper-level ridge axis continues to build eastward into the Upper Midwest.
However, models continue to hint at a mid-level shortwave trough trough to works its way down across the Upper Great Lakes later Tuesday. With this pattern there looks to be a low traversing into the Hudson Bay region and drag a cold front across the region. Given the more north to south trajectory of the cold front, expect it to be more in line with a backdoor cold front enhanced by the colder air off of Lake Michigan. Thus could see a quick drop in temps Tuesday afternoon into the evening with temps falling from 60s/70s into the 40s pretty quickly.
Additionally given the low-level WAA and southerly flow advecting in a bit more moisture into the southern WI, cannot completely rule out a few showers and storms to develop along this frontal passage. However, given the time differences and overall drier airmass aloft, will continue with the drier trend at this time.

Temps are expected to quickly recover into Wednesday as the upper- level ridge axis continues to build across the Upper Midwest through Thursday with highs exceeding 70F. Then long range models align and project an upper-level trough to dig down across the Canadian Plains and lift into the Upper Midwest later Thursday through the start of next weekend. Expect a more active pattern toward the end of the week with a return of showers and thunderstorm chances to southern WI later Thursday into Friday as the system traverses the region. Then behind this system toward the weekend looking at cooler temps behind the systems cold front.

Wagner

AVIATION
Issued 655 AM CDT Sun Apr 19 2026

An area of SCT snow flurries observed on radar is attempting to push into southern WI from the northwest this morning, though plenty of dry air is present beneath the associated 6,500 ft cloud bases and the majority of it should fall as virga.
Additionally, the current near-freezing surface temperatures will rise over the next few hours. Added some PROB30 groups to compensate for the flurries / sprinkles (I'm only ~30% confident it'll reach the ground at this time). Some isolated MVFR ceilings have been reported upstream, though the majority of the ceilings with the passing flurries / sprinkles should be VFR.

As the associated shortwave trough moves clear of the region this afternoon, expecting cloud cover to decrease and sprinkle activity to cease. Mostly clear skies and VFR tonight as a high pressure system builds overhead.

Sheppard

MARINE
Issued 1125 PM CDT Sat Apr 18 2026

Breezy northerly winds will continue across Lake Michigan for Sunday, especially across the northern third of the lake.
However, light winds are expected for the start of the week as high pressure works its way across the region through the day Monday. Then winds pick up for Tuesday. May see a conditions approach small craft level in southern WI nearshores as Tuesday, breezy southerly winds should develop over the region a cold front extending from a low pressure trekking across the Hudson Bay region Tuesday works its way down the lake turning winds more northerly behind it. However will be short-lived as high pressure builds in right behind it for midweek. Small craft conditions return for the end of the week as the pattern becomes a bit more active with a develop system trekking across the Upper Midwest bring stronger southerly winds along with showers and thunderstorms chances.

Wagner

MKX WATCHES/WARNINGS/ADVISORIES
WI...None.
LM...None.